Originally posted: February 22, 2011
Revised: May 29, 2011Warning: pic heavy, as usual. UPDATE APRIL 15, 2011: My review is based on an early engineering sample of the T20C, which contained the Cree XP-G R5 emitter. Sunwayman has decided to go with a XM-L T6 emitter in the shipping T20C.

Manufacturer specifications are unknown at this time

What you are looking at is an engineering sample of a new Sunwayman light, the T20C. It has some distinctive features, which I will describe below.

To give you a general idea up-front, the light uses a Cree XP-G R5 emitter and takes 2xCR123A, 2xRCR and 1x18650. It is a multi-mode light, with 3 constant output levels and one “hidden” strobe. But the switch is unique – it is silent (i.e. no click) and can do both momentary and constant on.

Also, the final appearance of the light may change for the shipping version. Sunwayman informs me there may be modifications at the mass production stage.

First off, I have no idea what packaging will be like, but I assume it will be fairly typical to other Sunwayman lights (i.e. you usually get at least a wrist strap, body clip, spare o-rings and boot cover, manual, and warranty card). Also no idea as to price yet.

What is most distinctive about the light is the switch. At first, I thought it was an electronic switch, since it was noiseless (i.e. no click). But it's not that simple, given given how it functions (i.e. half press for momentary, full press for lock-on).

In reality, it is something of a combination of an electronic switch in the head, with a mini-piston and a mechanical tailcap switch. If you look at the interior tailcap picture above, you will see two semi-circular areas on the perimeter of the switch spring that have a "L-shaped" pattern to them. These two areas rise when you press on the switch button.

So, when you first tighten the tailcap, the outside portion of the switch makes contact with the outer ring of of the body tube. As you press the button, eventually the raised switch areas make contact with the inner part of the body tube (which is actually a spring-mounted interior sleeve). Continue pressing, and sleeve makes additional contact with the head somehow. This is how the light apparently signals the difference between a momentary press, and locked-on. I'm not entirely clear on the circuit specifics, so please check with Sunwayman for more info.

For the current engineering sample, I would say it is a solidly made light. Annodizing is a shiny black instead of the classic Sunwayman natural (Sunwayman confirms the final version will be black). Knurling is reasonable, and the light comes with stainless steel bezel and tailcap rings. The light cannot tailstand. Tailcap threads are anodized for lock out.

Thanks to the spring in the head, flat-top cells work fine.

All in all, it is a fairly classic and classy looking build for a light this size.

The T20C apparently features the Cree XP-G R5 Cool White. The reflector is textured to what I would consider a medium orange peel (MOP). Given the overall size of the head, I would expect a fairly typical beam for this class of light.

UPDATE: Again, this review is based on an early engineering sample of the T20C, which contained the Cree XP-G R5 emitter. Sunwayman has decided to go with a XM-L T6 emitter in the shipping T20C. You should therefore expect greater max output and less throw from the XM-L emitter version (given that the build seems otherwise the same).

Which brings us to the requisite white wall hunting . All lights are on Hi on 18650 (AW Protected where available), about ~0.75 meter from a white wall (with the camera ~1.25 meters back from the wall). Automatic white balance on the camera, to minimize tint differences.

As you can see, a fairly typical beam for this size head. There are a few rings in the beam, but they are not distracting. Scroll down to my Summary Tables for more specifics on output and throw.

User Interface

To turn the light on in momentary-mode, depress the switch halfway. Fully depress the switch to lock-on in constant output. When the light is on, fully depress the switch to turn off the light

To change modes (when the light is on), hold the switch fully pressed. Within a second or so, the light will begin to cycle through its output modes in the following repeating sequence: Lo > Med > Hi. Release the switch to select the desired mode.

Light has memory, and retains the last mode selected next time you turn on the light.

Strobe mode is “hidden” – do a quick double-full-press of the switch to enter strobe. Turn off the light to exist. There is no memory for strobe (i.e. always comes back on at your memorize constant output level).

No PWM

I was unable to detect any signs of PWM with my setup. This suggests the light is current-controlled, or it uses a PWM freq beyond my ability to detect. Either way, nothing to worry about visually.

Strobe

Measured at a very high 23 Hz in my testing.

Testing Method:

All my output numbers are relative for my home-made light box setup, a la Quickbeam's flashlightreviews.com method. You can directly compare all my relative output values from different reviews - i.e. an output value of "10" in one graph is the same as "10" in another. All runtimes are done under a cooling fan, except for any extended run Lo/Min modes (i.e. >12 hours) which are done without cooling.

Effective November 2010, I have revised my summary tables to match with the current ANSI FL-1 standard for flashlight testing. Please see http://www.sliderule.ca/FL1.htm for a description of the terms used in these tables.

The max output and throw of the T20C are quite reasonable and consistent with its emitter and reflector design.

UPDATE: Again, this review is based on an early engineering sample of the T20C, which contained the Cree XP-G R5 emitter. Sunwayman has decided to go with a XM-L T6 emitter in the shipping T20C. You should therefore expect greater max output and less throw from the XM-L emitter version (given that the build seems otherwise the same). Runtime is hard to know, but I've noticed on other XM-L based lights that they don't typically seem to be any more efficient than XP-G lights, at lower drive currents.

Output/Runtime Comparison:

No surprises here – the overall output and output/runtime efficiency for the T20C are quite in keeping with this class of light.

Potential Issues

Switch feel takes a little getting used to – I find you need to fully press fairly hard to insure the light stayed locked-on, or to access strobe (i.e. double-full-press).

The switch is not absolutely silent (i.e. if you listen carefully, you can faintly hear the piston sliding).

Given the novel electronic switch/piston mechanism, it remains to be seen if additional issues crop up.

Preliminary Observations

The T20C is a solidly-built and solidly-performing member of the 2xCR123A/RCR 1x18650 class of XP-G R5 lights. It is a reasonably compact and tough-looking light (reminiscent of the Fenix TK12, but with a few extra design flourishes).

There are no real circuit surprises here – throw, output, and relative spacing of levels is pretty consistent with most lights in this class. Note however that some of the more recent builds in this class are driven harder on max, and have bigger and deeper reflectors for enhanced throw. I'm glad to see strobe is "hidden" by a double-click, the regular mode sequence is Lo > Med > Hi.

What distinguishes the T20C is the novel switch design – I don’t think I’ve seen this sort on tailcap piston before. I presume the main point of this switch is to insure relatively silent operation (important for all you closet ninjas out there ). But the mechanical piston may also be designed to enhance long-term longevity (i.e. no cheap plastic clicky switch to break).

Although I can’t comment personally on the need for silent operation, I can see the mechanical piston fitting in well with the other compact and sturdy aspects of the light. After all, clicky switches are often the weakest part of a light. Ultimately, it’s hard to know how well this sort of tailcap piston-drive will perform in comparison, but it has worked reliably in my testing so far.

Given this silent tailcap (and uber-fast strobe), I'm guessing the primary audience for this light is security/law-enforcement (i.e. a duty light). It looks to me like the body tube would fit in a standard 1-inch gun mount. The light certainly has a solid feel.

UPDATE APRIL 15, 2011: This review is based on an early engineering sample of the T20C, which contained the Cree XP-G R5 emitter. Sunwayman has decided to go with a XM-L T6 emitter in the shipping T20C. You should therefore expect greater max output and less throw from the XM-L emitter version (given that the build seems otherwise the same). Runtime is hard to know, but I've noticed on other XM-L based lights that they don't typically seem to be any more efficient than XP-G lights, at lower drive currents.

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